We present a hybrid method to efficiently solve Google Machine Reassignment problem (MRP), the problem proposed at ROADEF/EURO Challenge 2012 competition. We study, implement, combine and empirically examine different local search neighborhoods to solve the set of available instances. Intensification and diversification of search is achieved through the suitable change of the objective function...

In this paper we address the problem of parallelizing local search. We propose a general framework where different local search engines cooperate (through communication) in the quest for a solution. Several parameters allow the user to instantiate and customize the framework, like the degree of intensification and diversification. We implemented a prototype in the X10 programming language based...

We propose a dedicated tabu search algorithm (TSX_WDP) for the winner determination problem (WDP) in combinatorial auctions. TSX_WDP integrates two complementary neighborhoods designed respectively for intensification and diversification. To escape deep local optima, TSX_WDP employs a backbone-based recombination operator to generate new starting points for tabu search and to displace the searc...

Abstract Sustainable intensification aims to increase production and improve livelihoods of smallholder farmers in sub-Saharan Africa. Many farmers, however, are caught a vicious cycle low productivity lack incentives invest agricultural inputs. Moving towards sustainable therefore requires support such as input subsidies learning about new options through, for instance, co-learning approaches....

The knapsack problems are a classic NP-hard problem in the combinational optimization. Inspired by the conclusion of the cognitive psychology about the human memory system, a Tabu Search method based on Double Tabu-List (DTL-TS) has been proposed to solve it. With the addition of the search strategy of intensification and diversification, the excellent experiment results have been gotten. Compa...

Much of life's diversity has arisen through ecological opportunity and adaptive radiations, but the mechanistic underpinning of such diversification is not fully understood. Competition and predation can affect adaptive radiations, but contrasting theoretical and empirical results show that they can both promote and interrupt diversification. A mechanistic understanding of the link between micr...

This paper introduces a cooperative parallel metaheuristic for solving the capacitated vehicle routing problem. The proposed metaheuristic consists of multiple parallel tabu search threads that cooperate by asynchronously exchanging best found solutions through a common solution pool. The solutions sent to the pool are clustered according to their similarities. The search history information id...

This paper presents a guided cooperative parallel tabu search algorithm for solving the capacitated vehicle routing problem. In the proposed algorithm, knowledge is extracted from the previously found solutions and applied to guide the diversification and intensification of individual search threads. The computational experiments on two sets of large scale benchmark instances show that the prop...

The problem of curriculum-based course timetabling is studied in this work. In addition to formally defining the problem, we present a hybrid solution algorithm (Adaptive Tabu Search–ATS), which is aimed at minimizing violations of soft constraints. Within ATS, a new neighborhood and a mechanism for dynamically integrating Tabu Search with perturbation (from Iterated Local Search) are proposed ...

In this work, a new scatter search-based approach is studied for the NP-Hard satisfiability problems, in particular for its optimization version namely max-SAT. The paper describes a scatter search algorithm enhanced with a tabu search component combined with a uniform crossover operator. The latter is used to identify promising search regions while tabu search performs an intensified search of...